1. Field of the Invention
The present invention relates to a hollow golf club head.
2. Description of the Related Art
A hollow golf club head has been known. The hollow structure increases a head volume and a moment of inertia. For example, a so-called wood type, hybrid type, and utility type heads are usually hollow.
The volume of a hollow part is increased and the thickness of the head is thinned with the increase in size of the head. When the hollow part is great, a hitting sound is loud. Since the vibration of the head is great when the thickness is thin, the hitting sound is loud. The head increased in size causes a loud hitting sound.
Golf club heads considering a hitting sound have been proposed. A golf club head is disclosed, which has an inner surface having a rib provided thereon in order to obtain a good hitting sound. Japanese Patent Application Laid-Open No. 2006-204604 (U.S. Patent No. 2006/172818) discloses a curved rib extending to a heel side edge part of a sole from a toe side edge part thereof. Japanese Patent Application Laid-Open No. 2003-102877 discloses a rib provided in an abdominal part producing an out-of-plane secondary bending vibration in a sole part.